Understanding carbon isotopes

摘要

Almost all elements are made up of more than one isotope - i.e. atoms of the same element, but which have different masses. In fact, this is why most quoted atomic weights are not whole numbers, because they are average of a number of different atomic masses. Carbon is no exception and is made up of isotopes with masses 12, 13 and 14 (written as ~(12)C, ~(13)C, ~(14)C, but read as carbon -12, etc.)